1. Field of the Invention
The present invention relates generally to the field of mobile communication terminals, and specifically to a mobile communication terminal with an acoustic chamber for a hands-free speaker.
2. Brief Description of Related Developments
The demand for new features in portable communications equipment, such as mobile telephones, continues to rise, while the size of these devices remains the same or is required to become even smaller. Some of these new features relate to the audio aspects of mobile telephones. For example, integrated hands-free devices require a significant improvement in speaker quality and sound intensity compared with the earphone speaker arrangement provided in conventional mobile telephones. Similarly, an improvement in speaker quality is required as mobile telephone speakers are increasingly used to play polyphonic ring-tones, downloaded midi files, FM radio and so on.
An increase in speaker performance can be brought about by the use of an acoustic chamber, in much the same way as a conventional audio system loudspeaker requires a speaker enclosure. One particular requirement to the acoustic chamber is that it has to be completely sealed. Even small leakages will cause a significant decrease in the speaker performance and quality.
In prior art solutions it is known to use a permanently sealed box which is integrated in the cover, in an antenna unit or in the chassis of the phone. These usually plastic material prior art boxes have been sealed by ultrasonic welding or double sided adhesive gaskets, and if opened the box was destroyed. However, if the speaker is permanently integrated in the cover and for some reason it has to be repaired or needs maintenance, the whole cover (which could include the antenna), the whole chassis or the complete antenna unit, has to be exchanged.